Fifteen-year clinical experience with the biocor porcine bioprostheses in the mitral position

Background. Bioprosthetic valve use represents a crucial improvement in sur gical treatment of mitral valve disease. The aim of this study is to determ ine the long-term durability of the Biocor porcine bioprosthetic mitral val ve. Methods. Between 1985 and 1989, a total of 158 Biocor porcine bioprosthetic valves were placed in the mitral position, and long-term results of these patients were investigated retrospectively in 1999. Results. Thirty-day mortality was 4.4% (7 patients). Total follow-up was 1, 499 patient-years. Actuarial survival was 83.66% +/- 3% at 5 years, 77.78% +/- 3.36% at 13 years (1.8% patient-year), Multivariate analysis demonstrat ed younger age, duration of implantation, congestive heart failure, and fun ctional class to be significant predictors of late mortality. Actuarial fre edom from valve-related mortality was 98.58% +/- 1% at 15 years (0.13% pati ent-year). Actuarial freedom from structural valve deterioration was 95.49% +/- 1.8% at 5 years, 70.2% +/- 4.12% at 10 years, and 64.82% +/- 5.34% at 13 years (2.6% patient-year). Actuarial freedom from structural valve deter ioration-related reoperation was 98.43% +/- 1.1% at 5 years, 89.15% +/- 2.8 5% at 10 years, and 76.82% +/- 7.91% at 14 years. Multivariate analysis sho wed younger age and duration of implantation to be significant predictors o f structural valve deterioration and its related reoperation. Conclusions. By studying a 15-year time period, it is seen that this new ge neration porcine bioprosthetic valve should be considered an alternative fo r mechanical valves in selected patients. (C) 2001 by The Society of Thorac ic Surgeons.